The present invention relates to a single-chip microcomputer and, more particularly, to a technique which is effective when applied to a high-performance and high-function single-chip microcomputer suited for a home game machine or a portable data communication terminal device.
There is a single-chip microcomputer or a singlechip data processor in which a central processing unit, a direct memory access controller,(as will be shortly referred to as the "DMAC") and a peripheral circuit such as a variety of timers are constructed into a semiconductor integrated circuit device.
An example of this single-chip microcomputer is disclosed in "HITACHI Single-Chip RISC Microcomputer SH7032, SH7034 HARDWARE MANUAL" issued by Hitachi Ltd., in March, 1993.
Thanks to development of the semiconductor technology, a number of semiconductor elements can be formed over one semiconductor substrate. As a result, around the central processing unit, there can be formed peripheral circuits to enhance the performance and function. If, however, a number of peripheral circuits are simply packaged for higher performance and more functions, it has been found that disadvantages are caused from the standpoint of the operation speed or the power dissipation. Moreover, this microcomputer has to have its three-dimensional image processing function enhanced.